Cylinder hones



Sept. 10, 1968 .1. T. CLARK 3,400,500

CYLINDER HONES Filed July 15, 1966 Jaw-5 7' 64A .ez

' rron/v5) United States Patent 3,400,500 CYLINDER HONES James T. Clark, Fort Morgan, Colo., assignor to Clark- Feather Mfg. Co., Fort Morgan, Colo. Filed July 15, 1966, Ser. No. 565,525 4 Claims. (Cl. 51353) ABSTRACT OF THE DISCLOSURE A tool drive shaft having an arm-spreading disc fixed on its forward extremity and a spring actuated slide element slidably mounted thereon rearwardly of said disc, there being a plurality of flexible hone-supporting arm's projecting forwardly from said slide element through guide passages in said disc so that as said slide element is urged forwardly by said spring the forward extremities of said arms will be resiliently and radially expanded.

This invention relates to cylinder honing tools more particularly of the type illustrated in applicants prior Patent Nos. 2,778,168 and 3,065,579. Tools of this type are designed to be mounted in the chuck of a portable electric drill and inserted in a cylinder for honing the internal surface of the latter by means of circumferentially-traveling hone stones to remove surface glaze and increase the efliciency of the pistons and piston rings operating therein.

Conventional cylinder hones consist of a plurality of pivotally mounted relatively stiff arm carrying hone stones with various means for resiliently urging the arms outwardly into contact with the cylindrical wall. This necessitates a relatively large number of assembled parts and since the hones operates at relatively high speeds and are subjected to exceedingly rough usage the stiff pivotally mounting arms become bent and loosened from their pivots, so as to misalign the hone stones.

The principal object of this invention is to eliminate the troublesome arm pivot elements of the usual hone and provide simple easily assembled resilient arms so contoured that they will be automatically and resiliently urged outwardly as they are moved forwardly so as to reduce the cost of manufacture and increase the life of the hone.

A further object is to provide a cylinder hone with hone-supporting arms which will inherently and resiliently flex in a radial direction and yet will be firmly braced in a circumferential direction so as to avoid arm breakage bending when being inserted in and rotated in a cylinder.

When a conventional cylinder hone is withdrawn from a cylinder the arms will snap radially outward and must be manually contracted for insertion in the next successive cylinder. A still further object of this invention is to provide means for limiting the diameter of spread of the arms when they are withdrawn from a cylinder so as to facilitate insertion in the next cylinder to be honed.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is made to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

FIG. 1 is a side elevational view of the improved cylinder hone in a partially expanded position;

FIG. 2 is an enlarged, fragmentary, vertical, longitudinal section through the right hand portion of FIG. 1;

FIG. 3 is a similar longitudinal section showing the hone in a more expanded position;

FIG. 4 is a detail rear face view of a spring-actuated slide element employed in the hone;

FIG. 5 is a similar detail front face view of the element of FIG. 4;

FIG. 6 is a detail rear face view of an arm spreader disc employed herein;

FIG. 7 is a similar detail front face view of the ele ment of FIG. 6;

FIG. 8 is a detail top plan view of a hone supporting arm as employed in this invention;

FIG. 9 is a detail front end view of the arm of FIG. 8;

FIG. 10 is a detail rear end view of the arm of FIG. 8; and

FIG. 11 is a perspective view of a retaining wedge to be later described.

The cylinder hone of this invention employs a chuck stud 12 adapted to be chucked in the chuck of a c ventional drill. The stud 12 is flexibly connected by means of a length of flexible shafting 13 to a tool drive shaft 14. The forward extremity of the drive shaft is reduced in diameter to form a shoulder 15 from which a threaded terminal stud 16 concentrically projects.

The drive shaft is provided with series of tool-actuating threads 17 positioned in rearwardly spaced relation to the shoulder 15 to receive a knurled spring-compressing nut 18 which is threaded thereon. An arm-spreading disc 19 is threaded on the stud 16 tightly against the shoulder 15 and a slide element 20 is constantly and resiliently urged toward the disc 19 by means of a compression spring 21 which surrounds the drive shaft 14 between the nut 18 and the disc 19 and fits over a spring centering sleeve 22 formed on the rear face of the slide element 20 and the disc 19 cooperate to support and actuate three similar elongated hone-supporting arms 23.

Each arm 23 is stamped from semi-resilient relatively stiff spring metal to form a narrowed, upturned, hooklike, rear extremity 24 and a downwardly-facing channel 25 at its forward extremity. Adjacent the upturned extremity 24, the metal is pressed to form a forwardly extending, straight rear portion 26 which is transversally flat and extends upwardly and forwardly from the portion 26 at an angle of substantially 32 to form an inclined portion 27 terminating in a transverse apex or ridge 28 from which the metal inclines downwardly, to form a descending portion 29, thence straight forwardly to the channel 25.

The arm spreading disc 19 is provided with three equally spaced arm guide passages 30 adjacent its periphery thru which the arms 23 pass. The inner or axial wall of each passage, as the rear face of the disc 19 is approached, is inclined inwardly toward the axis to produce an inclined surface 31. The outer circumferential wall of each passage 30 is notched back from the forward face of the disc to form peripheral notches 32 about the forward face of the disc.

The forward face of the slide element 20 is counterbored to form a circular, concentric sunken socket 33 the circular peripheral wall of which is internally grooved to form an annular internal groove 34 with its open side facing axially.

Each of the arms 23 extends through one of the passages 30 with its inclined portion 27 facing the inclined surface 31 of the passage and with its upturned extremity 24 engaged in the groove 34 of the element 20 as shown by the upper arm in FIG. 2. Thus, when the slide element is forced forwardly on the drive shaft 14 the three arms will be simultaneously forced forwardly and their inclined portions 27 will ride up the inclined surfaces 31 of the passages 30 to spread the forward extremities of the arms, as shown in FIG. 3. A hone support 35 is tiltably mounted over the channel of each arm by means of a hinge rivet 36 and an elongated hone stone 37 is cemented or otherwise mounted on the outer face of the hone support as is customary in cylinder hones.

It can be seen from the above that if the free extremities of the three hone arms 23 be compressed together for insertion in a cylinder the inclined portions 27 thereof will slide axially down the inclined surfaces of the arm passages 30, as the upturned extremities 24 pry outwardly in the annular groove 34, so as to push the slide element rearwardly against the bias of the spring 21. When the arms are released within the cylinder they will expand so that the hone stones will be resiliently forced outwardly against the cylinder wall under the bias of the spring 21. The spring acts to force the arms forwardly so that the inclined portions 27 of the arms will travel radially outward on the inclined surfaces 31 of the passages to expand the free extremities of the arms. The degree of expansion and the pressure against the cylinder wall can be preset and regulated by varying the position of the nut 18 on the drive shaft 14.

The upturned extremities of the arms are permanently retained in the annular groove 34 since the inner extremities of the arms will contact the drive shaft before the upturned extremities leave the retaining groove. In fact, when assembling, the upturned extremities must be in place in their retaining groove before the drive shaft is passed forwardly through elements 19 and 20.

It will be noted that the terminal stud 16 projects forwardly from the disc 19. This is simply for convenience should it be desired to employ an extension rod 41 thereon such as shown in broken line in FIG. 3 and as fully described in applicants copending application Ser. No. 426,057.

It has been found to be annoying to have the arms snap open when the honing tool is withdrawn from a cylinder. This can be avoided by providing the tool with a retaining wedge device, such as illustrated in FIG. 11, which can be inserted around the shaft 13 between the slide element 22 and the disc 19 before the hone stones are withdrawn from the cylinder.

The wedge device illustrated comprises a flat plate 38 provided with a notch 42 at one extremity and a hanging hole at its other extremity. The parallel sides of the plate 38 are turned upwardly, as shown at 39, and the upper edges of the sides are similarly inclined to provide a wedge effect. In use, the notched extremity of the plate 38 is forced between the sliding element 20 and the spreading disc 19 so that the inclined sides 39 will wedge the element 20 and the disc 19 apart to prevent spreading of the arms until the tool is inserted in the next succeeding cylinder.

While a specific form of the invention has been described and illustrated herein, it is to be understood that the same may be varied within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention what is claimed and desired to be secured by Letters Patent is:

1. A cylinder hone comprising:

(a) a drive shaft;

(b) an arm-spreading disc concentrically afiixed on the forward extremity of said drive shaft;

(c) arm-receiving passages formed in said disc;

'(d) a slide element slidably mounted on said drive shaft rearwardly of said disc;

(e) a compression spring surrounding said drive shaft rearwardly of said slide element;

(f) a spring-compressing nut threaded on said drive shaft rearwardly of said spring and acting to compress said spring into engagement with said slide element to urge the latter toward said disc;

(g) a plurality of similar hone-supporting arms in engagement with said slide element at their rear extremities and extending forwardly and outwardly through the arm-receiving passages in said disc so that when said slide element is moved toward said disc said arms will slide forwardly and outwardly through the passages in said disc so as to spread their forward extremities apart;

(h) means for mounting a hone upon the forward extremity of each arm;

(i) an outwardly-facing, hook-like, rear extremity on each of said arms; and

(j) an inwardly facing socket in said slide element into which the hook-like rear extremities of said arms are engaged.

2. A cylinder hone as described in claim 1 in which the inwardly facing socket comprises:

(a) a concentrically positioned, circular, sunken socket in the forward face of said slide element having a raised annular edge; and

(b) an annular inwardly facing retaining groove formed in said edge into which the hook-like rear extremities of said arms are engaged.

3. A cylinder hone as described in claim 1 having:

(a) an inclined contact surface in each of said passages inclined forwardly and outwardly from the axis of said disc; and

(b) an inclined portion in each of said arms positioned to contact and slide forwardly on the inclined surface of its respective passage to urge the forward extremity of said arm outwardly from the projected axis of said drive shaft.

4. A cylinder hone as described in claim 2 in which the depth of the retaining groove and the height of the outwardly-facing, hook-like, rear extremity on each arm are so related that when the rear extremity of the arm is moved radially inward toward the drive shaft, it will contact the latter shaft before the outwardly-facing, hooklike extremity thereof leaves said groove so as to prevent removal of said arms from said slide element when said drive shaft is in its assembled position.

References Cited UNITED STATES PATENTS 2,157,421 5/1939 McFarland 15104.l8 2,736,146 2/1956 Brooks 51-341 2,778,168 1/1957 Clark 51332 3,065,579 11/1962 Clark 51-331 3,251,623 5/1966 Fredholm 294-97 ROBERT C. RIORDON, Primary Examiner.

DONALD G. KELLY, Assistant Examiner. 

